A holding device for a ferromagnetic container body open at both ends is known for transport on a conveyor with which the container body can be conveyed through a processing or treatment zone, especially through an electroimmersion bath.
To transport a container body open on both ends by a conveyor carrying it, e.g. to feed it through a processing zone or to convey it through a treatment zone, the container bodies are usually positioned comparatively closely together on the conveyor standing upright and are secured by lateral strips on the conveyor to prevent sliding.
With container bodies made of ferromagnetic material the conveyor can be constructed as a so-called magnetic band conveyor which holds the container bodies in their position on the conveyor because of magnetic forces.
To be sure magnetic band conveyors are more suitable for a container body having only one end open made of ferromagnetic material when these are transported sitting on its base on the conveyor. This is because only in this position magnetic forces act effectively on the container body to guarantee a secure holding of the container body in an upright position. With a container body open on both ends and conveyed upright on the magnetic band only comparatively small magnetic and/or holding forces are developed.
If in a single step of the conveyor a direction change upwardly or downwardly occurs, conveyors without magnetic holding forces are completely unsuitable. Using magnetic band conveyors the holding forces effective on a container body open on both ends are still more strongly reduced in the vicinity of the direction changes of the conveyor since the container body no longer stands completely upright on the conveyor.
The known conveyors are completely unsuitable for attaining and maintaining a reliable mounting of a container body on the conveyor for transport of the container body through the immersion bath and for transport through other treatment zones in which the container body should be acted on all sides by a treating medium, for example in drying, and are usable only by making allowances for considerable disadvantages.
Because of these problems a special holding device as described in German Open Application DE-OS 20 24 106 for immersion treatment of container bodies open on both ends has been developed. These holding devices are positioned above the immersion bath and comprise two planar sieve like carriers running parallel to each other between which the container bodies are received and lowered jointly with the sieve carriers into the treatment fluid.